Leak-proof drinking cup and lid assembly

ABSTRACT

A leak-proof drinking cup and lid assembly is taught which effectively prevents any liquid from escaping the interior chamber of the cup. The leak-proof drinking cup and lid assembly comprises a cup and a lid, where the lid is adapted to seal the cup by screwing onto the cup and contacting at least two distinct radial sealing areas on the cup. The leak-proof cup and lid assembly allows for vigorous shaking and mixing of the cup&#39;s contents in addition to transportation of the contents without leaking. A preferred embodiment further incorporates a blending disk to improve mixing of the contents.

CROSS REFERENCE

This application cross references corresponding U.S. design Patent No ______, filed on Oct. 30, 2007, the disclosure and contents of which are expressly incorporated herein by reference.

FIELD OF THE INVENTION

In the modern, industrialized world, there is considerable need for leak-proof drinking cups with removable lids. People are increasingly mobile and want the ability to transport and consume a beverage while doing such activities as driving, walking, running, or hiking. Likewise, there is much demand for a leak-proof cup that allows vigorous shaking and mixing of the cup's contents. Many diet beverages, nutritional supplements and baby formulas require the mixing of a dry powder with a liquid just prior to consumption. Cups for these uses are often known as shaker cups and require a leak-proof lid.

BACKGROUND OF THE INVENTION

The current drinking cup and lid assemblies on the market are only marginally leak-proof. Many designs exist which have a snap-on lid. If precisely engineered and manufactured and if used extremely carefully, some of these designs can have a degree of leak resistance. However, snap-on lids, regardless of how well they are designed and manufactured, have an inherent flaw. Because the lid merely pushes onto and weakly attaches to the cup, snap-on lids routinely fail with rugged or aggressive use. In most of these instances, failure is total and complete with the snap-on lid popping off of the cup and its contents spilling or splattering over the surroundings.

For instance, several snap-on designs currently exist for sports-related shaker cups which are used to mix protein and nutritional beverages. These shaker cups are often used to blend a beverage at home and then the shaker cup and its contents are placed haphazardly in a gym bag. At this point, if the shaker cup is poorly designed, a leak could potentially ensue. If the shaker cup is well designed and does not initially leak, one of several problematic scenarios can still likely occur. If the gym bag and shaker cup are placed in a hot environment like the interior of a car on a hot day, the interior of the shaker cup can build up pressure from the expansion of gases within the shaker cup. In this situation, the pressure of the gases can cause the snap-on lid to pop off the cup base which then allows the contents to spill into the gym bag. Likewise, if the gym bag is thrown around or handled roughly, the snap-on lid can inadvertently pop off. It has also been observed on occasion that if the shaker cup is shaken too vigorously in an effort to blend the contents of the shaker cup, the snap-on lid can pop off, thus randomly releasing the contents of the cup into the air and onto the surrounding environment.

A leak-proof drinking or shaker cup that uses a physical mechanism to lock the lid onto the cup is desired. One solution is a screw-on lid. Drinking and shaker cups currently exist that use screw-on lids; however, these designs are flawed because they do not satisfactorily prevent leaks. One design uses a radial rubber or polymer gasket that sits in a radial groove in the screw-on lid. In this design, the top edge of the shaker cup becomes pressed against this rubber gasket and creates a seal. Seemingly, this would be an effective design against leaks. In most instances, drinking and shaker cups with this design do not initially leak. However, with continual use, the gasket becomes misshapen, worn out, or brittle which consequently causes the cup to leak. Another problem with this design is that the gasket must be removed after use in order to properly clean the radial groove and all parts of the gasket. Once removed, the gasket tends to be extremely difficult to re-insert correctly into the groove.

Several existing screw-on lid drinking and shaker cup designs currently do not use a gasket. Although they are not plagued with the problems of the gasket-type variety, they are not sufficiently leak-proof to be used confidently and consistently in everyday use. All current designs use one radial sealing surface in the screw-on lid that seals with one surface at the top of the cup base. The surface at the top of the cup base that is used for sealing is usually the top edge or inside edge. The problem with having only one sealing area is that the methods used to mass produce plastic items such as cups are not incredibly precise. A true leak-proof seal requires one of the surfaces at the top of the cup base to be completely and thoroughly sealed against a mating surface on the screw-on lid. For this situation to exist, all areas of the sealing surfaces must be extremely uniform and smooth. Any bumps, irregularities or scratches can create a situation that allows for leaks.

Another problem is that heat from automatic dishwashers routinely shrinks and/or warps the shape of the cup base and screw-on lid. Once this occurs, it is nearly impossible to obtain a full, air tight seal as the original design is no longer true to form and the sealing surfaces do not perfectly align. This deficiency with the current designs of screw-on lid drinking and shaker cups creates a situation whereby it is impractical or frustrating to use the cup. Drinking cups and shaker cups on the market today leak when shaken or leak when turned upside down or put on their side. These cups obviously pose a problem for a person that wishes to randomly put the shaker cup into a bag and/or travel with it to a final destination. It also poses a problem for drinking cups designed for infants. These cups are routinely thrown, turned upside down or left on their side for long periods of time. The drinking cups for infants currently on the market do not address the annoying leaking problems that occur with having only one radial sealing surface.

A need exists for drinking and shaker cup and lid assemblies that are completely and thoroughly devoid of leaks. There is a need for an anti-leak design that is robust enough so that even with vigorous use and numerous encounters with the high heat of an automatic dishwashing machine, the cup will not leak.

SUMMARY OF THE INVENTION

The drinking and shaker cup and lid assembly of the present invention creates a very robust and air-tight seal between the screw-on lid and the cup. The seal is strong and secure enough to handle the most rigorous of shaking as well as preventing any leaking liquids from escaping even if the cup is turned upside down for extended periods of time. Furthermore, this superior design allows the seal to remain functional even after numerous encounters with high heat, such as what is encountered in an automatic dishwashing machine.

Whereas prior art describes and uses only one sealing surface, the drinking and shaker cup and lid assembly of the invention uses two or more sealing surfaces. The invention includes a leak-proof drinking cup and lid assembly comprising a cup and a lid adapted to seal the cup by screwing onto the cup and contacting at least two distinct radial sealing areas on the cup. The invention also comprises a lid for sealing a cup which is attachable to the cup by screwing onto radial threads on the cup, wherein the lid contacts at least two distinct radial sealing areas on the cup and prevents liquids in the cup from leaking out of the cup. Although difficult to properly engineer and manufacture, having two sealing surfaces provides much needed redundancy which makes the sealing system extremely robust and resistant to leaks.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a cross-section view of prior art showing a lid attached to a cup using the top edge of the cup as a sealing surface.

FIG. 2 is a cross-section view of prior art showing a lid attached to a cup using the inner edge of the cup as a sealing surface.

FIG. 3 is a cross-section view of prior art showing a lid attached to a cup using the outer edge of the cup surface as a sealing surface.

FIG. 4 is a cross-section view of a cup showing a lid attached to a cup using the top edge of the cup and inside edge of the cup as sealing surfaces.

FIG. 5 is a cross-section view of a cup showing a lid attached to a cup using the top edge of the cup and the outside edge of the cup base as sealing surfaces.

FIG. 6 is a cross-section view of a cup showing a lid attached to a cup using the inside edge of the cup and the outside edge of the cup as sealing surfaces.

FIG. 7 is a cross-section view of a cup showing a lid attached to a cup using three sealing surfaces on the cup: the top edge, the inside edge and the outside edge.

FIG. 8 is a top view of the cup showing the positioning of the blending disk.

FIG. 9 is a top view of the blending disk.

FIG. 10 is a side view of the blending disk.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

FIGS. 1, 2 and 3 show examples of prior art cup and lid assemblies. These designs use only one sealing surface between the lid 3 and the cup 2. FIG. 1 shows the sealing surface on the top edge 1 of the cup 2 while FIG. 2 demonstrates a seal that uses the surface on the inner edge 5 of the cup 2. FIG. 3 shows a cup 2 designed to use only the outer edge surface 6 of the cup for a sealing surface. The sealing ability of the lid 3 shown in FIG. 3 is even less effective than using the top edge 1 alone or the inside edge 5 alone.

FIGS. 4, 5, 6 and 7 show examples of the four possible designs that conform to the scope of this invention. FIGS. 4, 5 and 6 demonstrate designs based on a lid 3 contacting at least two distinct radial sealing areas on the cup 2. FIG. 4 shows a lid 3 contacting the top edge 1 of the cup 2 and inside edge 5 of the cup 2 as sealing areas. FIG. 5 shows a lid 3 contacting the top edge 1 of the cup 2 and the outside edge 6 of the cup as sealing areas. FIG. 6 shows a lid 3 contacting the inside edge 5 of the cup 2 and the outside edge 6 of the cup 2 as sealing areas. FIG. 7 demonstrates a design based on a lid 3 contacting three sealing points, which include the top edge 1, the inside edge 5 and the outside edge 6.

The invention provides for a drinking or shaker cup 2 and lid 3 assembly that is completely leak-proof. Unlike prior designs which only use one radial sealing point, the designs according to this invention use two or even three radial sealing points. The radial sealing points are shown in FIGS. 4, 5, 6 and 7. The radial sealing points include the top edge 1, the inside edge 5 and the outside edge 6 of the cup 2. These sealing surfaces are sealed when the lid 3 is screwed onto the cup 2 through radial threads 4. The multiple sealing points are superior in that they provide a much greater surface area to allow for an air tight seal. Furthermore, they allow for redundancy in the sealing process. Therefore, even if one seal is slightly out of specification or damaged during the manufacturing process or is slightly warped from contact with high heat, the other seal is present for full sealing. When two or more seals are employed, the seals tend to push against one another and become self-locking. This characteristic of a multiple sealing system creates a sealing system that is very secure, robust and is nearly 100% effective against leaks or seal failure.

The sealing system as set forth can be used in any type of drinking cup or shaker cup including drinking cups for infants, drinking cups for sports related activities such as hiking, running and biking, shaker cups for sports and medical related beverages such as protein shakes, meal replacements, and amino acid formulations, and shaker cups for other food related items such as pancake, pudding and gelatin mixes. The lid to the cup can include all variations of leak-proof spouts known in the industry.

In a most preferred embodiment, the shaker cup also incorporates a blending disk 21 as shown in FIGS. 8, 9 and 10. While the blending disk 21 can be made from any material safe for use with food such as metals, plastics, resins, etc, in a preferred embodiment, the blending disk comprises a molded plastic disk comprising a grid or screen 22. The blending disk can be positioned anywhere inside the cup, but is most preferably positioned just under the lid for ease of removal. In one embodiment the disk contains projections 23 which allow for easy grasping of the disk when it is inserted into the cup. When shaken, solid and liquid materials inside the cup are further agitated, mixed or broken up upon coming in contact with the blending disk. This ensures more uniform mixing of components than if the blending disk was not present. One of skill in the art will appreciate that the blending disk can take forms other than a grid or screen as long as the blending disk is capable of further agitating the contents upon shaking.

Plastic polymers that can be used to produce the drinking and shaker cups and lid assemblies of this invention include polyethylene, polypropylene, polystyrene, polyurethane, polyester, polycarbonate, nylon and high technology derivatives of these polymeric resins. All varieties of polyethylene work especially well with this invention and include high density, medium density, low density, linear low density, very low density, ultra low density, and metallocene linear low density. In some instances, it may be advantageous to use two different polymers; one for the screw-on lid and one for the cup base. For instance, if an odor-free sports drinking cup was desired, it would be ideal to use polycarbonate for the cup base and polyethylene for the screw-on lid.

Accordingly, it will be understood that the preferred embodiment or embodiments of the present invention have been disclosed by way of example and that other modifications and alterations may occur to those skilled in the art without departing from the scope and spirit of the appended claims. 

1. A leak-proof drinking cup and lid assembly comprising: a cup; and a lid adapted to seal the cup by screwing onto said cup and contacting at least two distinct radial sealing areas on the cup.
 2. The leak-proof drinking cup and lid assembly of claim 1, wherein said drinking cup and lid assembly is manufactured from a plastic resin.
 3. The leak-proof drinking cup and lid assembly of claim 1, wherein said lid is adapted to seal the cup by contacting at least three distinct radial sealing areas on the cup.
 4. The leak-proof drinking cup and lid assembly of claim 1, wherein said cup and lid assembly is used as a shaker to mix liquids by shaking the contents.
 5. The leak-proof drinking cup and lid assembly of claim 1, wherein said cup and lid assembly is used to transport liquids.
 6. The leak-proof drinking cup and lid assembly of claim 1, wherein at least two distinct radial sealing areas on the cup are selected from the group consisting of: a top edge, an inner edge and an outside edge.
 7. The leak-proof drinking cup and lid assembly of claim 1, further comprising a blending disk.
 8. A lid for sealing a cup which is attachable to said cup by screwing onto radial threads on said cup, wherein said lid contacts at least two distinct radial sealing areas on the cup and prevents liquids in said cup from leaking out of said cup.
 9. The lid of claim 8, wherein at least two distinct radial sealing areas on the cup are selected from the group consisting of: a top edge, an inner edge and an outside edge.
 10. The lid of claim 8, wherein the lid and cup are manufactured from a plastic resin.
 11. The lid of claim 8, wherein the lid contacts at least three distinct radial sealing areas on the cup and prevents liquids in said cup from leaking out of said cup.
 12. The lid of claim 8, wherein the lid and cup are used as a shaker to mix liquids by shaking the contents.
 13. The lid of claim 8, wherein the lid and cup are used to transport liquids.
 14. A leak-proof drinking cup and lid assembly comprising: a cup; a lid adapted to seal the cup by screwing onto said cup and contacting at least two distinct radial sealing areas on the cup; wherein at least two distinct radial sealing areas on the cup are selected from the group consisting of: a top edge, an inner edge and an outside edge.
 15. The leak proof drinking cup and lid assembly of claim 14 further comprising a blending disk.
 16. The leak proof drinking cup and lid assembly of claim 15 wherein the blending disk comprises an insert containing a mesh grid.
 17. The leak proof drinking cup and lid assembly of claim 16 wherein the cup contains an internal ledge for positioning the blending disk. 